This invention relates to medical instrumentation in general and more particularly to an improved system for providing on-line acquisition, analysis and topographical display of the electrical activity generated by the human brain in real time.
The measurement of the electrical activity of the human brain and the preparation of an output representing this activity is known. A presentation, normally formed on a chart which has as one axis time and the other axis voltage, is known as an electroencephalogram (EEG). In order to develop an EEG one or more pairs of sensors are provided and attached to the subject's head. In a typical system, there can be a single reference electrode and as many as 16 other electrodes for each hemisphere of the brain. The result when recording data from these electrodes is a chart with up to 32 different traces which then must be analyzed by a neurologist, psychiatrist, etc. This, of course, is time consuming and in no case allows real time analysis.
Similarly, there have been attempts to provide a topographic display of brain activity. Such is carried out by obtaining data from electrodes and providing that data to a computer which then analyzes the data and provides output information for a topographic display. However, once again, a display of the brain activity which can be analyzed in real time is not possible. One can only look at the activity at predetermined points in time long after the brain activity has ceased.
The desirability and need for a device which will provide a topographical display in real time to neurologists, psychiatrists, etc. should be evident. With such a device, the physician can stimulate the patient and observe the reaction of the brain to various activities. Similarly, the condition of the brain in various states such as sleep, coma, etc. can be instantly observed by the physician. In addition, it is desirable that an instrument of this nature be capable of recognizing abnormal conditions and be able to store the display for reviewing after certain specified conditions take place.
Thus, it is the object of the present invention to provide a system which meets all these requirements.